Mechanical vibrator



NOV. 13, 1956 STANTON 2,770,760

MECHANICAL VIBRATOR Filed Aug. 11, 1953 INVENTOR Ausf/n' N. Stanton ATTORNEY Patented Nov. 13, 1956 MECHANICAL VIBRATOR Austin N. Stanton, Garland, Tex.

Application August 11, 1953, Serial No. 373,567

Claims. (Cl. 317-182) This invention relates to mechanical vibrators and more particularly to a mechanical vibrator which may be used as a frequency standard.

An object of this invention is to provide a new and improved mechanical vibrator.

Another object of this invention is to provide a new and improved mechanical vibrator having a very stable frequency of vibration.

Still another object of the invention is to provide a new and improved mechanical vibrator including an annulus of magnetic material supported at spaced points to allow circumferential distortion of the annulus in directions perpendicular to the central axis of the annulus.

A still further object of the invention is to provide a new and mechanical vibrator, of the type described, wherein a coil energized by a periodically fluctuating electrical current maintains the annulus in vibration.

Other objects and advantages of the invention will become apparent as the description proceeds taken in connection with the accompanying drawing wherein:

Figure 1 is a side plan view of the mechanical vibrator;

Figure 2 is a sectional view taken on the line 22 of Figure 1;

Figure 3 is a sectional view taken on line 33 of Figure 2;

Figure 4 is a top plan view of the mechanical vibrator having a coil mounted therein to drive the vibrator; and

Figure 5 is a sectional view taken on the line 5--5 of Figure 4.

Referring now to the drawing, the mechanical vibrator may be made of a single integral magnetic body which includes an annulus 11 mounted on a circular base 12. The annulus 11 is connected to the base 12 by four thin connector members 13 which are equally spaced about the circumference of the annulus and which are less thick than the annulus. The annulus, connector members and the base 12 may be formed from a cup shaped piece of stock by milling out the undesired portions of the stock.

The base 12 is provided with a pair of parallel slots 14 and 15 which extend downwardly through the base and communicate with a rectangular recess 16 in the bottom of the base so that a band 17 may be inserted through the slots to secure a coil 18 to the base. The ends of the band 17 overlap and are secured to one another either by solder or by a suitable clip, not shown. The longitudinal central axis XX of the coil is aligned perpendicularly to, and intersects, the central axis YY of the annulus and lies in the central plane ZZ of the annulus so that the magnetic force generated by an electric current flowing through coil will serve to pull the opposed sections a of the annulus toward each other as is shown in broken lines in Figure 4. To intensify the magnetic field to which the sections a are subjected, a magnetic core 19 is inserted in the coil. When the sections a are moved to the broken line positions, the opposed sections b tend to move to their broken line positions of Figure 4 since the annulus, of course, is made of a magnetic resilient substance, such as steel.

When the coil 18 is de-energized, the sections a and b move back to their original positions and having gained appreciable velocities continue moving in the same directions, sections a outwardly and sections b inwardly, beyond their original positions. This vibrational movement is facilitated by the disposition of the connecting members 13 at the four nodes of this vibrational move- 1 ment of the annulus.

If the current in the coil 18 fluctuates at the natural 7 frequency of vibration of the annulus in this mode, the

annulus may be set and maintained in vibration by a relatively small current in the coil.

The mechanical vibrator may be used in any applications employing mechanical vibrators. .For example, it may be used in a filter circuit since the impedance of the coil 18 will be greatest when the current in the coil fluctuates at a frequency substantially equal to the natural frequency of vibration of the mechanical vibrator.

It may also be employed to generate as alternating current of a very stable frequency in the same manner as tuning forks are employed, as for example in the circuit shown in Figure 5 in the patent to J. J. Murray, No. 2,574,188. In this case, a pair of pick-up coils 20 would be disposed adjacent the sections b to detect their movement and generate an alternating potential which is amplified and employed to energize the coil 18. The coils 20 would serve the same function as the pick-up coils 16 and 17 shown in the circuit of Figure 5 in the patent to J. J. Murray, Jr., and the coil 18 would serve the same function as the driver coils 14 and 15.

If desired the base 12 and the connector members 13 could be formed of a non-magnetic material, such as brass, to eliminate the leakage of magnetic flux between opposite ends of the coil 18 through the base plate and the connector members.

The annulus 11 could also be of two welded or bonded rings of two substances having different and compensating variations in their moduli of elasticity with variations in temperature so that the natural frequency of vibration of the annulus would be constant over substantial ranges of temperature.

It will now be seen that a new and improved mechanical vibrator has been illustrated which includes an annulus supported at four points along one edge so that it is free to vibrate about nodes at these four points. It will also be seen that the vibrator may be formed of a single cup-shaped piece of stock and that coil 18 may be easily mounted on the base by means of the band 17 and the apertures or slots 14 and 15 of the base in operative position with respect to the annulus so that energization of the coil by an electric current may set the annulus in vibration.

It will be apparent that various changes and modifications may be made in the described and illustrated mechanical vibrator without departing from the invention and it is intended, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A mechanical vibrator including: an annulus of resilient magnetic substance; and means for supporting said annulus at four substantially equally spaced points along one edge of said annulus, opposed sections of said annulus being resiliently movable toward and away from one another about four nodes disposed at said points.

2. A mechanical vibrator including: an annulus of resilient magnetic substance; means for supporting said annulus at four substantially equally spaced points along one edge of said annulus, opposed sections of said annulus being resiliently movable toward and away from one another about four nodes disposed at said points; and electromagnetic means disposed within said annulus for causing a pair of said opposed sections to move toward and away from one another.

3. A mechanical vibrator comprising: a base plate; an annulus of resilient magnetic substance; four connector members supporting said annulus on said base plate, said connector members being secured to said annulus at four substantially equally spaced points along the edge of said annulus, opposed sections of said annulus being resiliently movable toward and away from one another about fou nodes disposed at said points. v

4. A- mechanical vibrator comprising: a base plate; an annulus of resilient magnetic substance; four connector members supporting said annulus on said base plates, said connector members being secured to said annulus at'four substantially equally spaced points along the edge of said annulus, opposed sections of said annulus being resiliently movable toward and away from one another about four nodes disposed at said points; and

, I J ,4 4 electromagnetic means disposed Within said annulus for causing a pair of said opposed sections to move toward and away from one another.

5. A mechanical vibrator comprising: a base plate; an annulus of resilient magnetic substance; four connector members supporting said annulus on said base plates; said connector members being secured to said annulus at four substantially equally spaced points along the edge of said annulus, opposed sections of said annulus being resiliently movable toward and away from one another about four nodes disposed. at said points; and a coil mounted on said base and disposed within said annulus, said coil having a central longitudinal axis perpendicular to the central axis of the annulus.

References Cited in the file of this patent UNITED STATES PATENTS 

